Some of the material in is restricted to members of the community. By logging in, you may be able to gain additional access to certain collections or items. If you have questions about access or logging in, please use the form on the Contact Page.
Three dimensional scalar heightfields, also known as volumetric datasets, abound in science and medicine. Viewing the isosurfaces, or level sets, is one of the two main ways to display these datasets, the other being volume visualization. Typically the isosurfaces are rendered on a personal computer (PC) allowing the scientist or doctor analyzing the dataset to interactively change the isovalue, and rotate or zoom the isosurface. Unfortunately, out of necessity due to the PC's video card, current techniques render the isosurfaces with a basic hardware-accelerated lighting model. This lighting model lacks important features such as shadows, and as a result the isosurfaces are more difficult to interpret than if they had been rendered with a physically based lighting model. My thesis is that isosurfaces can be displayed with realistic illumination at interactive rates on a typical PC. I present a method for applying global illumination to interactively created isosurfaces, using a physically based lighting model, with a negligible increase in the time required to render the isosurfaces. The result is convincing shading that is easy to interpret by the human visual system, including features such as soft shadows, inter-reflection, caustics, and color bleeding. This is achieved by solving the rendering equation for all isosurfaces within the volume, storing the solutions in a 3D texture, and then texture mapping the result onto a polygonal approximation of the isosurface. This process is called "heightfield rendering".
Shape From Shading, Global Illumination, Photon Mapping, Texture Mapping, Level Set, Isosurface
Date of Defense
July 26, 2005.
Submitted Note
A Thesis Submitted to the Department of Computer Science in Partial FulfiLlment of the Requirements for the Degree of Master of Science.
Bibliography Note
Includes bibliographical references.
Publisher
Florida State University
Identifier
FSU_migr_etd-1175
Use and Reproduction
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them.